1. Field of the Invention
The present invention generally relates to improvements in control of a distribution system, and more specifically to the use of intelligent autonomous nodes to monitor and control the distribution of material or energy.
2. Description of Related Art
In general, a distribution system comprises one or more sources connected through a distribution network to one or more delivery points. As the commodity (material or energy) is transported through the network, abnormalities (e.g., faults) may develop that can lead to a disruption of the normal flow of the commodity or a loss of the commodity from the system. In order to help minimize the effects of these abnormalities, a distribution system will typically have nodes at various locations throughout the network which operate to monitor or control the flow of the commodity through the system.
It is desirable to not only minimize the loss of the commodity when an abnormality occurs, but also to minimize the number of users who experience an interruption of the delivery of the commodity due to any abnormality. In order to reduce the loss of the commodity, the nodes in a system may have the capability to respond individually to system abnormalities without coordinating with other nodes. In such a system, nodes can prevent the commodity from flowing through the part of the distribution system where the abnormality exists. However, this system may interrupt service to more users than is absolutely necessary.
Each node may also communicate with a central control location which gathers information from each node and coordinates a system-wide response. In such centrally controlled systems, the central controller typically maintains a detailed map of the system topology, and this map must be updated whenever the system is reconfigured or new nodes are added. This can make such centrally controlled systems difficult and costly to implement and maintain. Additionally, for small systems with few nodes, the need to include a central controller can significantly add to the cost of the system.
Furthermore, once an abnormality is rectified, the nodes typically must be transitioned to a normal state or to a specified state. Once the abnormality is corrected, it is generally desired to place the nodes in the original configuration or a specified configuration, at present this is typically done manually.
What is needed is a distribution system in which nodes can be easily added, subtracted, or reconfigured and which can control the nodes of a distribution system in order to configure them to minimize the loss of the commodity and maximize the number of users served in the presence of an abnormality. Additionally, what is needed is a control system that can restore nodes into their normal operating state or any other specified state after the abnormality has been rectified.
Also what is needed is a distribution system in which the nodes can act independently and without a central controller. Preferably the nodes would locally store information about the system required to enable a node to react to system abnormalities and the information would be coded to ensure its reliability.
Furthermore, what is needed is a distribution system in which nodes that malfunction can remove themselves from coordinated system activities. Preferably when the malfunction in a node is rectified the node should be able to resume normal operation as part of the system.
Additionally, what is needed is a system that requires only one Messaging step in order to begin restoring service to users.